1. Field of the Invention
The present invention is directed to methods and apparatus for optimizing images with an apparent depth and, more particularly, to methods and apparatus which use one or a combination of several techniques to minimize image jump or stutter in depth images.
2. Description of the Related Art
Images which have an apparent depth can be produced in a number of different ways. Images produced using integral, lenticular and barrier technology suffer from a problem commonly called image jump or stutter as the point of view of the viewer of the image shifts. This problem can be partially understood by using FIG. 1 which shows a cross sectional view through an integral or lenticular photograph. Portions of the images 1-4, originally photographed from different image taking viewpoints, are formed on a photographic media 10. These portions of the images are projected into viewer space by a faceplate 12, sometimes called an overlay or faceplate, which has formed on one surface a series of cylindrical or spherical refracting surfaces having a positive diopter power. The curvature of the refracting surfaces and the faceplate thickness is predetermined by design to establish a local lens focal length substantially equal to faceplate thickness. Therefore, images coincident with the rear surface of the faceplate will be projected to an infinite conjugate on the opposite side. The combination of the curved surface and the faceplate material could be considered as a lens or lenslet and the entire assemblage an array of lenses or lenslets. In the special case of lenslets formed as parallel cylinders, the lenslets are commonly called lenticules, therefore in the case of a lenticular photograph the images 1-4 on substrate 10 positioned under each lens 14 are thin linear slices of the original photographs (or images captured) and the lenses 14 are cylindrical. In the case of an integral photograph, the images 1-4 on substrate 10 are circular portions of the original photographs and the lenses 14 are spherical. Because the images 1-4 formed on the substrate 10 are discrete portions of the original images, as the viewpoint of the viewers shift from viewpoint 1 to viewpoint 2, a transition or jump occurs between the images. This sudden shift makes the photograph seem less real.
The jump problem is even more apparent when objects in the original scene are separated depth wise by a significant distance. This further problem is illustrated and exaggerated in FIG. 2 in which two objects 16 and 18, when photographed through two cameras 20 and 22 (or a single camera with multiple lenses), produce two images 24 and 26. Between these two images 24 and 26, not only does the position of object 16 in the foreground move or displace toward the right a distance d.sub.1, but the position of object 18 in the background displaces a different distance d.sub.2. If the viewer is viewing these images through a lenticular or integral faceplate on a photograph and concentrates attention on the object 16, for example a person, when the view jumps between images 24 and 26, object 18, which could be a tree behind the person, will experience a large displacement or shift. This shift of objects at a distance behind the attention or focal point also makes the photographs seem less real.
Prior art systems for capturing multiple images and creating depth images have typically used optical capturing system (cameras) and optical printing systems (enlargers with special mirrors). Such systems are not capable of moving images or portions of images relative to each other or of creating images in between the actually captured images. That is, the prior art optically based systems are incapable of solving the image jump or stutter problem.